Conventionally, there has been proposed a recording medium feeding device provided with a one-way clutch which switches a driving power on or off in order to push up a bottom plate, on occasion of separating and feeding sheets of paper, thereby to elevate a sheet, and in order to push down the bottom plate before feeding a next sheet (see JP-A-2000-103525, for example)
The recording medium feeding device disclosed in JP-A-2000-103525 includes a bottom plate for pressing sheets of paper against a paper feeding roller, a separating pad for separating and feeding the sheets of paper one by one, a bottom plate driving mechanism associated with the paper feeding roller in order to make the bottom plate contacted with or separated from the paper feeding roller on every occasion of feeding a sheet of paper, and a friction member provided on an upper face of the bottom plate. This bottom plate driving mechanism includes a lever for moving the bottom plate up and down, a rotary cam for moving the lever in association, and a clutch mechanism for intermittently transmitting a driving power to the rotary cam. The clutch mechanism for intermittently transmitting the driving power to the rotary cam is a one-way clutch having a spring clutch and a solenoid device. In a state of waiting for the paper feeding, the driving power is not transmitted from the one-way clutch to the rotary cam, and the rotary cam is not be rotated. As a result, the lever which presses one end of the bottom plate downward is not be released, and the one end of the bottom plate is kept in a waiting position against a spring which urges the bottom plate. In this state, on occasion of feeding the paper, the driving force is transmitted from the one-way clutch to the rotary cam, thereby to rotate the rotary cam. Consequently, the lever which is pressing the one end of the bottom plate downward is released, and the one end of the bottom plate is elevated toward the paper feeding roller under a spring force of the spring. Then, the sheet of paper is pressed by the paper feeding roller to be fed. When final two sheets of paper are separated and fed, a sheet of paper in a lower stack is pressed against the friction member of the bottom plate by the pressing lever. In this manner, multiple feeding of the sheets of paper is restrained. As described above, it is possible to move the bottom plate up and down at appropriate timing, and multiple feeding of the sheets of paper can be prevented by means of the friction member and the pressing lever, even when the final two sheets of paper are remained. Moreover, because the lower sheet of paper is pressed with the bottom plate, friction between the lower sheet of paper and the bottom plate is increased, and therefore, it is possible to prevent the lower sheet of paper from being fed together with the upper sheet of paper, even though the friction member is not provided on the bottom plate.